Liquid-fuel burner



W. A. DOBLE.

LIQUID FUEL BURNER.

APPLICATION FILED JULY 16, 1919.

Patented Mar. 29, 1921.

2 SHEETS-SHEET l- IN.VENTOR um bOBLE, Q

'HIS ATTORNEYS W. A. DOBLE.

LIQUID FUEL BURNER.

APPLlCATlON FILED JULY 16, 1919.

Patented M815 29, 1921.

2 SHEETSSHEET 2.

INVENTOR BY WA. DOBLE! H15 A TTORNEYS UNITED STATES PATENT OFFICE.

WILLIAM A. DOBLE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR'TODOBLE LABORA-TORIES, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNLIQUID-FUEL BURNER.

Specification of Letters Patent. Pate t d M 29. 1921 Application filedJuly 16, 1919. Serial No. 311,138.

To all whom it may concern.

Be it known that I, WILLIAM A. DOBLE, a citizen of the United States,and a resident of the city and county of San Francisco, State ofCalifornia, have invented a certain new and useful Liquid-Fuel Burner,of which the following is a specification.

The invention relates to liquid fuel burners.

An object of the invention is to provide a burner in which the air forcombustion is heated to a high temperature by the flame, before it comesinto the flame.

Another object of the invention is to pro vide a burner in which thefuel is sprayed and in which the air for combustion is intimately mixedwith the sprayed fuel, before the mixture reaches the combustion zone.

Another object of the invention is to provide a burner in whichcombustion of the fuel occurs over a large distributed area.

The invention possesses other advantageous features, some of which, withthe foregoing, will be set forth at length in the following description,where I shall outline in full, that form of the invention which I haveselected for illustration in the drawings accompanying and forming partof the present specification. In said drawings I have shown one specificform of burner of my invention, but it is to be understood that I do notlimit myself to such form, since the invention, as expressed in theclaims, may be embodied in a plurality of forms.

Referring to said drawings:

Figure 1 is a vertical section of the burner of my invention.

Fig. 2 is a cross section of the burner, taken on the line 2-2, Fig. 1.

The burner shown in the accompanying drawings, and which embodies myinvention, comprises an outer casing or shell 2, preferably formed ofcast iron. The shell 2 is preferably circular in shape and isprovided atthe bottom with a central opening through which the air for combustionenters the burner. Arranged within the shell 2 and spaced from thebottom and side walls thereof and supported in position by the posts 3,is an inner shell or casing 4, preferably made of cast iron. The innerand outer shells are similar in shape and inclose between them, anannular passage 5, through which the air for combustion passes upwardly.Arranged between the bottom walls of the two casings and directly overthe aperture in the outer casing, is a blower 6, wh1ch blows airupwardly through the annular passage 5. The blower is secured to theshaft 7 of the motor 8 which is sup ported upon the bracket 9, securedto the outer .casmg. The inner casing 4 is provlded 111 the bottom withone or more holes 12, through which unvaporized liquid fuel drains intothe outer casing. The bracket 9 s provided with a passageway 13',opening 1nto an annular groove 14 surrounding the air lnlet and anyliquid collecting in the groove passes through the passage 13 and isconveyed by the pipe 15 to the supply tank or other suitable receptacle.At starting, when the burner is cold, some of the fuel may remain inliquid form and this fuel is dramed from the burner, as stated. Theinner casing 4 is provided with an inner annular wall 16 and within thiswall and mounted on the motor shaft 7 is a rotatable metallic cup orbowl 17, into which the liquid fuel is fed and from the edge of which itdischarges in a fine spray, in all directions, radially. The liquid fuelis delivered to the cup 17 through the pipe 18, by the pump 19 which isgeared to the motor shaft 7, so that the amounts of air and fuelintroduced into the burner vary simultaneously with the speed of themotor, thereby maintaining the proportion of air to fuel substantiallyconstant at all times.

The outer casing 2 is provided at its upper edge with a flange 21, theupper surface of wh1ch is preferably disposed above the upper edge ofthe inner casing 4. Secured to the flange 21 is an annular cap 22 havinga curved upper wall 23 and an inwardly and downwardly inclined innerannular wall 24 which forms the wall of the fire box or combustionchamber. The walls 23 and 24 are s aced from the inner wall 4, form theinner wall, a continuation of V the annular air passage. 'The inner walling, wit

24 preferably terminates slightly above the plane of the rim of the cup17. The cap 22 is provided on the inner face of the wall is thus exposedto the air traveling through the passage, causin the temperature of theair to be raised to a igh degree. The radial fins 26 also act as airguides, to check any swirling movement of the air and cause it to bedischarged in relatively straight streams into the inner casing 4. Theentering downwardly directed air is deflected upwardly into thecombustion chamber by the bottom and inner wall of the casing l.

The spray of finely divided fuel particles. dischargingradially from theedge of the cup 17, is directed through two streams or heated air, sothat the fuel is vaporized and intimately mixed with the air. The fuelfirst comes in contact with the upwardly deflected stream of air andthat which is not arrested and carried along with the ascending stream,passes into the descending stream issuing from the annular passagewaywherein the fuel is vaporized.

Mbans are provided for igniting the combustible mixture of air andliquid fuel. Secured to the outer casing 2 by the clamp nut 27 andinsulated therefrom by the block 28 of insulation, is an electrode rod29. the inner end of which lies adjacent the side of the cup 17, whichforms the other electrode. One side of the ignition circuit is connectedto the rod 29 and the other side is grounded on the burner casing. Aspark is formed between the stationary and rotatable electrodes, whichignites the mixture. 1 have found it desirable to protect the sparKagainst the high velocity incoming air and for that purpose, I inclosethe rod in a tube 31 which is firmly held in place and which extends toadjacent the end of the rod. The tube is cut away at the top on itsinner end to permit the entry of the combustible mixture to the arc andto provide an exit for the igniting flame.

I claim:

1. In a liquid fuel burner, an outer metallic casing having a rentrantannular upper wall,-an inner metallic casing forming an annular passagewith the outer casing, fins on the other casing extending into saidpassage, means for blowing air through said passage, and means for addinliquid fuel to the air to produce a comliustible mlxture.

2. In a liquid fuel burner, an outer casing, an inner casing, a cap onthe outer casing overlying the upper ed e of the inner casing, an airblower arranged between sa1d casings arranged to blow air through thepassage between the casin s and into the inner casing, and means wit inthe inner casing for directing a spray of fuel into the air stream.

3. In a liquid fuel burner, a bowl-shaped outer casing having a centralaperture therein, a bowl-sha ed inner casing spaced from the outercasing and forming therewith an annular assage, means for blowing airthrough sai passage, an annular cap arranged on the outer casing andoverlying and spaced from the inner casing for defiecting the air intothe inner easing, and means within the inner casing for directing aspray of fuel into the air stream after at has traversed said passage.

In a liquid fuel burner, a bowl-shaped alter casing, a bowl-shaped innereaslng spaced from the outer casing and forming therewith an annular airpassage, means arranged between the casings for blowing air through saidpassage, an annular cap arranged on the outer casing and overlying theupper edge of the inner casing to deflect the in downwardly into theinner easing, an inrier wall on said cap defining a combustion 'namber.fins on said walls lying in said passageway. means in the inner casingfor di- "acting a spray of fuel into the air stream to produce acombustible mixture, and means for igniting sa1d mixture.

3. In a liquid fuel burner, an outer bowlshaped casing, an innerbowl-shaped easing forming an annular passage with the outer casing, acap on the outer casing overlying the upper edge of the inner casing andforming a ree'ntrant passage in continuation of the annular passage. awall on the inner periphery of said cap defining a comoustion chamber.fins on sa1d wall extending into the reentrant passage, means for blow-;ng air through said passages. means for directing a fuel spray into theair stream as it discharges from said reentrant passage whereby acombustible mixture is produced, and means for igniting said mixture.

i. In a liquid fuel burner, an outer bowlshaped casing, an innerbowl-shaped casing spaced from the outer casing and forming "herewith anannular passage, a blower for ilowing air through said passage, a. capon the outer casing arranged to deflect the air iownwardly into theinner casing, an inner wall on said cap defining a combustion chamberand means for introducing a liquid fuel spray into the combustionchamber.

In a liquid fuel burner. an outer bowlshaped casing, an innerbowl-shaped casing spaced from the outer casing and forning therewith anannular passage, a blower for blowing air through said passage, a cap onthe outer casing arranged to deflect the air downwardly into the innercasing, an inner wall on said cap defining a combustion chamber. andfins on the outer surface. of said wall extending into the air passage.

t. In a liquid fuel burner, an outer bowlshaped casing, an innerbowl-shaped easing -paced from the outer casing and forn'iing therewithan annular passage, a blower for blowing air through said passage, a capon the outer casing arranged to deflect the air iownwardly into theinner casing. an inner wall on said cap defining a combustion chamber,fins on the inner surface of said wall extendin into the combustionchamber and fins on t e outer surface of said wall extending into saidpassage. 9. Ina liquid fuel burner, an outer casing, an inner casingspaced from the outer nected to the motor for feeding liquid fuel to thecup.

10. In a liquid fuel-burner, an outercasing, an.inner casing, means fordischargin a fuel spray into the inner casing anf toward the side wallthereof, said inner casing being provided with a drain hole fordeposited liquid fuel, a groove in the outer casing adapted to receivethe drained li uid and a discharge conduit'connected to sa1d groove.

11. In a liquid fuel burner, a'metallic wall defining a combustionchamber, means for producing an ignited combustible mixture of air andliquid fuel in. said chamber whereby said wall is heated, metallic finson the outer surface of said wall, and means for causing the air whichis to form part 7th day of July,

defining a combustion chamber means for producing an ignited combustiblemixture ofair and liquid fuel in said chamber whereby said wall isheated, metallic fins on the inner surface of said wall, metallic finson the outer surface of said wall, and means for causing the air, whichisto form part, of the combustible mixture, topass in contact with.saidouter fins.

13. In a liquid fuel burner, an outer cas ing, an inner casing, arotatable metallic cup arranged within the inner casing, said cupconstituting an electrode, means for feeding liquid fuelto said cup, astationary electrode mounted on and insulated from the outer casing andextending through the wall of the inner easing into close proximity tosaid cup, and means for producing a spark between said stationary androtatable electrodes.-

In testimony whereof I have hereunto set my hand at San Francisco,California,this

WILLIAM A. DOBLE.

In presence of- W..W. HEALEY, H. G. P110511.

152. Ina liquid fuel burner, a metallic wall of said mixture to pass incontact with said

